Bank note processing machines are used for sorting, destroying, dispensing, depositing, etc. bank notes. As a rule the bank notes to be processed are provided in the form of stacks, which are singled in the bank note processing machines. The single bank notes are collected by a transport system and transported through the bank note processing machine for processing. An apparatus for checking bank notes formed by one or several acoustic, electrical, optical, magnetic, mechanical, etc. sensors, can determine information about the bank notes allowing statements on the type, the state, the authenticity etc. of the bank notes. This information from the sensors is evaluated by a control unit. The further processing of the bank notes in the bank note processing machine takes place in dependence on the evaluation of the information.
The mechanical components of the bank note processing machine, for example the drive of the transport system, partly cause strong vibrations, sound, etc., also having an influence on the apparatus for checking bank notes, since these are connected to the bank note processing machine. Thereby the vibrations, the sound, etc. cause an acceleration of the apparatus for checking bank notes or of the sensors contained therein. This in turn has the consequence that the measurements by highly sensitive sensors can be disturbed, therefore worsening the signal-noise ratio of the measuring signals.